Containers employed in the food and beverage industry will typically include a removable lid to allow access to the container's contents. Thus, during typical automated container filling operations, food or beverage items are first placed into an awaiting empty container, and thereafter conveyed to a so-called "lidding" station where lids are removably secured to the container.
One specific example of conventional lidding stations is in connection with the automated production of frozen dessert cones, such as that described in U.S. Pat. No. 4,188,768 to Getman (the entire content of which is expressly incorporated hereinto by reference). In general, frozen dessert cones are produced by intermittently advancing a nested cone assembly (comprised of the frustroconically shaped edible prebaked cone and its conformably shaped paper overwrap) through a succession of stations. Thus, for example, an atomized spray of chocolate (or other flavored syrup) may be sprayed on the interior surfaces of the edible cone prior to the cone being filled with a freezable dairy product. Thereafter, a topping of chocolate (or other flavored syrup) and nuts may be applied immediately upstream of a lidding station. The finished product is then ejected from its conveyance track and subjected to freezing conditions.
The lidding station of the Getman '768 patent essentially has rotatable arms which are rotatable into engagement with a lowermost closure lid stacked in a magazine assembly aligned thereabove. In such a manner, the closure lid may be captured at the end of the rotatable arms by means of vacuum. However, when it is desired to place the closure lid onto the awaiting filled cones, separate means must be actuated by a timing mechanism in order to drive the arms downwardly to engage the closure lids held by the arms with the cone rims. (See column 6, lines 36-44 of the Getman '768 patent).
Although the lidding station disclosed in the Getman '768 patent is sufficient for its intended purpose, some improvements would be desirable. For example, it would especially be desirable if the rotational and upward/downward movements of the lid pick-up arms could be provided by a single, constant-rate reciprocal drive mechanism so that the relatively complex and separate timing/drive systems proposed by Getman '768 patent could be eliminated. It is towards providing such lidding station improvements that the present invention is directed.
Broadly, the present invention is directed toward systems whereby a container lid may be transferred from a supply stack and be repositioned relative to an awaiting container using a substantially constant-rate reciprocal drive. In such a manner, separate timing and/or drive assemblies required in the prior art to rotate and to vertically lower/raise the lid pick-up arms may be eliminated.
More specifically, the present invention includes a reciprocally displaceable mounting block carrying a rotatable transfer arm. The transfer arm, in turn, carries a pick-up head so that the pick-up head is rotatable with the transfer arm. The pick-up head rotation is controlled by a rack-and-pinion mechanical control assembly having a pair of opposed compression springs, a gear rack mounted between the opposed compression springs, and a pinion gear meshed with the gear rack and connected to the transfer arm. The gear rack includes a control rod which is slidably coupled to the mounting block during reciprocal displacements thereof. However, the mounting block will come into contact with travel limit stops provided at each end of the control rod so that during the final travel of the mounting block during its reciprocal movement, the mounting block and gear block will be locked as a unit and be displaced against the bias force of one of the springs. In such a manner, therefore, mechanical timing and control of the pick-up head rotation and its displacement relative to the stack of container lids and the awaiting container is provided.
These, and other aspects and advantages of the present invention will become more clear from the following detailed description of the preferred exemplary embodiments thereof.